A new need arose from the growth of accessibility to books: how to deal with contradictory information. One solution has been the ‘gloss’, which consisted in adding comments in small cursive on the side of a text. Another solution that appeared in the XII century was called ‘summa’ or summary, which purpose was to cut “the diverse interpretations to establish a core of truth” (Hobart and Schiffman, 2000): it began with a question, then contrasting opinions were listed and it ended with a conclusion or ‘sententia’.